Adjustable supporting structure for power tools or the like

ABSTRACT

A supporting structure for a portable boring machine has a foot which is attracted to a metallic body by one or more electromagnets and has a dovetailed circumferential groove. A column which supports the machine has a base abutting against the foot and having a circumferential groove for complementary flanges provided on two semicircular sections of a clamping ring. The sections have dovetailed flanges which extend into the groove of the foot and they are coupled to the base for rotation with the column relative to the foot. The sections can be moved into and out of clamping engagement with the foot and with the base, and the width of those flanges which extend into the groove of the base exceeds the depth of such groove to permit sidewise adjustments of the column when the clamping action is relaxed or terminated. The column is then also free to rotate about its own axis but through less than a full revolution. Sidewise adjustments of the column are effected by a spindle which is rotatable in one of the sections and extends radially of the column into a tapped bore of the base, or by a pinion which is rotatable with a shaft mounted in one of the sections and meshes with a radially extending rack of the base. The spindle and the internal threads of the bore or the pinion and the rack furnish a self-locking action so that the column can be moved sideways only when the spindle or the pinion is caused to rotate.

United States Patent Pahlow Oct. 24, 1972 [54] ADJUSTABLE SUPPORTING STRUCTURE FoR POWER TOOLS oR THE LIKE [72] Inventor:

many

[73] Assignee: Firma Wilhelmsbnrger Maschinenfabrik, Hinrichs & Sohn, Geesthacht, Germany 22 Filed: July 1,1971

21 Appl.No.: 158,871

[30] Foreign Application Priority Data March 4, 1971 Germany ..P 21 10 239.6

[52] US. Cl ..248/16, 173/32 [51] Int. Cl ..E2lc 5/00 [58] Field of Search ..248/23, 16, 206 A, 178, 285;

Lothar Pahlow, Geesthacht, Ger- Primary Examiner-J. Franklin Foss Attqrriey-'-Michael S. Striker {57] ABSTRACT A supporting structure for a portable boring machine has a foot which is attracted to a metallic body by one or more electromagnets and has a dovetailed circumferential groove. A column which supports the machine has a base abutting against the foot and having a circumferential groove for complementary flanges provided on two semicircular sections of a clamping ring. The sections have dovetailed flanges which extend into the groove of the foot and they are coupled to the base for rotation with the column relative to the foot. The sections can be moved into and out of clamping engagement with the foot and with the base, and the width of those flanges which extend into the groove of the base exceeds the depth of such groove to permit Sidewise adjustments of the column when the clamping action is relaxed or terminated. The column is then also free to rotate about its own axis but through less than a full revolution. Sidewise adjustments of the column are effected by a spindle which is rotatable in one of thesections and extends radially of the column into a tapped bore of the base, or by a pinion which is rotatable with a shaft mounted in one of the sections and meshes with a radially extending rack of the base. The spindle and the internal threads of the bore or the pinion and the rack furnish a self-locking action so that the column can be moved sideways only when the spindle or the pinion is caused to rotate.

- 10 Claims, 4 Drawing Figures PATENTED um 24 I972 SHEEI 2 IF 4 Inventor:- oonm PHHW n) 110/01! II #07 PATENTEDUBI 2.4 1912 3.700. 1 9'5 SHEET u or 4 BACKGROUND OF THE INVENTION plus The present invention relates to improvements in supporting structures for power-operated machines, such as portable power drills or the like. More particularly, the invention relates to improvements in supporting structures of the type wherein the machine is mounted on a supporting member which is adjustable with reference to a foot and wherein the foot is provided with one ormore electromagnets for securing it to a metallic plate or another metallic body.

German patent No. 1,128,257 discloses a supporting structure which is used to adjustably carry a boring machine and has a footprovided with electromagnet means for securing it to a metallic plate or the like. The connection between the foot and the supporting member or column for the machine is such that the column is rotatable relative to the foot so as to move the tool of the machine into any one of a practically infinite number of positions along a circle having its center on the axis of the column. In addition, the column is movable sideways relative to the foot so as to enable the operator to locate the tool of the boring machine in any desired position with reference to a workpiece which is to be provided with a tapped or untapped bore or hole. The column can be clamped to the foot in response to manipulation of a lever and the same lever is actuatable to terminate the clamping engagement between the column and the foot so that the column is then ready to be adjusted angularly and/or sideways. A drawback of such proposal is that it is difficult to maintain the column in a selected lateral position during angular adjustment, or vice versa. This will be readily appreciated since it is practically unavoidable to change the lateral position of the column while the latter is rotated with reference to the foot or to change the selected angular position of the column while the latter is moved sideways. The situation is aggravated when the foot is magnetically attracted to a vertical or nearly vertical surface because, once the lever is moved in a direction to terminate the clamping engagement between the foot and the column, the operator must carry the entire weight of a relatively heavy boring machine plus the weight of the column while the latter is being adjusted angularly and/or sideways. It is clear that such adjustment, while the weight of the machine and the column is being borne by the operator, consumes much time and can be carried out only by a strong person. As soon as the column is free to slide with reference to the foot while the latter adheres to a vertical surface so that the column extends substantially horizontally the weight of the boring machine invariably causes the column to assume its lowermost position. It is equally difiicult to maintain the column and the machine in a selected position of angular and lateral adjustment during the ensuing manipulation of the lever in order to establish a requisite clamping engagement between the column and the foot. t

It was further proposed to connect the column with the foot by means of a clamping device which comprises two arcuate sections having first flanges which extend into a complementary recess of thefoot and second flanges extending into a circumferential groove of the column. The two sections of, the clamping device are pivotally coupled to each other so that they can move into and from requisite frictional engagement with the foot and with the column. The center of the space within the sections is not located on the axis of the column. The column can be adjusted angularly when the frictional engagement between the sections of the clamping device and the foot is relaxed. A sidewise adjustment of the column takes place in response to rotation of the sections about the axis of the foot; such sidewise adjustment is due to provision of the aforementioned eccentric space. The arrangement is such that the interengaging portionsof the sections of the clamping device and the column furnish a self-locking action so that the lateral adjustment of the column remains intact while the column is;caused to turn with reference to the foot.

A drawback of such proposal is that the sidewise adjustment of the column with reference to the foot takes place along an arcuate path so that the placing of the tool of a boring machine into a selected position consumes much time and must be carried out on a trial and error basis.

German Utility 'Model No. 1,800,564 discloses a further supporting structure which is provided with separate adjusting means for angular and lateral positions of the column. However, the large number" of parts in such supporting structure contributes to its initial cost which is so high as to render the structure unattractive for widespread use.

SUMMARY OF THE INVENTION An object of the invention is to provide a relatively simple, compact, inexpensive, rugged and reliable supporting structure which allows forrapid and accurate positioning of a tool or the like in any desired position with reference to a workpiece and wherein the angular adjustment of the supporting member for a machine or the like remains intact during sidewise adjustment, or viceversa.

Another object of the invention is to provide the improved supporting structure with novel means for effecting sidewise adjustments of the supporting member with reference to the foot while the latter is being attracted to a metallic body by one or more electromagnets.

A further object of the invention is to provide the supporting structure with novel means for limiting the angular movements of the supporting member with reference to the foot.

An additional object of the invention is to provide a supporting structure wherein the manipulation of a single member suffices to establish or terminate the necessary clamping engagement between the foot and the supporting member.

The invention is embodied in a supporting structure for portable boring machines or other types of poweroperated tools. The supporting structure comprises a foot having one or more electromagnet means energizable to attract the foot to a metallicplate or another metallic body and a circumferential groove located in a plane which is preferably normal to the axis of the foot and preferably having a dovetailed cross-sectional outline, a supporting member in the form of a column or the like which is arranged to support a machine (preferably in such a way that the machine is adjustable lengthwise of the column), the column having a preferably'cylindrical base which abuts against one end face of the foot in the region of the first groove and is provided with a second circumferential groove preferably located ina plane which is normal to the axes of the-foot and column, a ring-shaped clamping device having two arcuate (preferably semicircular) sections provided with first flanges (preferably having'a dovetailed shape) extending into the first groove and second flanges extending with a certain amount of radial clearance into the second groove to hold the base of the column against movement away from the foot, tenclamping device with the base of the column for angular movement therewith, and self-locking adjusting means comprising a rotary first portion provided in or on one of the sections and extending substantially at right angles to the axis of the column and a mating second portion provided in or on the base and arranged to move with the base sideways in response to rotation of the first adjusting portion while the tensioning means maintains the sections of the'clamping device out of clamping engagement with the base and the foot.

The first portion of the adjusting means may comprise aspindle which is provided with a readily accessible handgrip portion and extends radially of the base, and the second portion of the adjusting means then comprises an internally threaded part of the base which meshes with the spindle. In accordance with another embodiment of the invention, the first portion of the adjusting means comprises a pinion rotatable about an eccentric axis which crosses in space with the axis of the base and the second portion then comprises a toothed rack .which meshes with the pinion and extends substantially radially of the base.

The novel features which are considered as characteristic of the invention are set forth in particular in the appended claims. The improved supporting structure itself, however, both as to its construction and. its mode of operation, together with additional features and advantages thereof, will be best understood upon perusal of the following detailed description of certain specific embodiments with reference to the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 4 is a horizontal'sectional view as seen in the direction of arrows from the line IV-IV of FIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring first to FIGS. 1 and 2, there is shown a supporting structure which includes a supporting member in the form of'a column 1 the upper portion of which carries a boring machine or another power tool, not shown. The machine is preferably adjustable in the longitudinal direction of the column L'The lower end portion of the column 1 forms a cylindrical base 2 which is provided with a circumferential groove or recess 5 located above a disk-shaped circular extension 3. The depth of the groove 5 (as considered in the radial direction of the extension 3) is indicatedat a. The axis of the extension 3 is shown in FIG. 1 as coinciding with the axis 4 of a foot 6. The underside of the extension 3 abuts against and is slidable relative to the upper side of a disk-shaped circular extension 8 forming part of the foot 6 which latter is formed with recesses for one or more coils 7 of electromagnet means serving to attract the foot 6 to a metallic plate or another metallic body, not shown, when the machine on the upper portion of the column 1- is to be put to use. The extension 8 is formed with a dovetailed circumferential groove 80 for I the complementary dovetailed flanges 11a, 12a of semicircular sections 9, '10 of a clamping ring. The sections 9, 10. are preferably mirror-symmetrical to each other and respectively provided with second semicircular inwardly extending flanges l1, 12 which extend into threaded spindle 13 having a stern which .is rotatable in FIG. 1 is a fragmentary partly elevational and partly the section 9 and extends radially of the axis 4. The outer end portion of the. stem of the spindle 13 is connected with a handgrip'member or knob 17 which is readily accessible at the outer side of the section 9. The spindle 13 extends into a tapped bore 14 of the extension 3 so that the latter is slidable in directions transversely of the axis 4 in response to rotation of the knob 17 when the frictional engagement between the sections 9, 10 and the extensions 3, 8 is relaxed. That part of the extension 3 which is provided with the bore 14 constitutes a second portion of the adjusting means and mates with the spindle 13 in all angular and lateral positions of the column 1 with reference to the foot 6. The follower 16 can be mounted in the section 9 or 10 and the channel 15 is then provided in the base 2.

The upper side of the section 10 is formed with a radially extending channel 15 for a pin-shaped follower 16 which is'secured to the base 2. The channel 15 confines the extension 3 (and hence the entire column 1) to substantially radial movement with reference to the axis of the extension 8 in response torotation of the spindle 13 by way of the knob 17. Thus, the follower l6 and the channeled portion of the section 10 constitute a coupling which compels the sections 9, 10 to share the angular movements of the column 1, and vice versa.

The sections 9, of the clamping ring are connected to each other by a pin, screw or a like member corresponding substantially to the member 25 shown in FIG. 4. The other ends of the sections 9, 10 are coupled to each other by means of a tensioning lever such as the lever 24 shown in FIG. 4. The arrangement is such that, when the tensioning lever is turned in one direction, the frictional engagement between the dovetailed flanges 11a, 12a of the sections 9, 10 and the extension 8 of the foot 6 is relaxed. When the tensioning lever is turned in the opposite direction, the dovetailed flanges 11a, 12a of the sections 9, 10 are moved into strong frictional engagement with the extension 8 to thus prevent any angular and/or sidewise movement of the column 1. The pivotal'movements of sections 9, 10 relative to each other are minimal but they suffice to allow for the generation of a strong frictional clamping engagement with the extension 8 or to permit convenient rotation of the column 1 about its axis. Such rotary movement is shared by the sections 9, 10 due to the provision of the coupling means including the channel and follower 16 on the one hand and the adjusting spindle 13 on the other hand. When the aforementioned tensioning lever is turned in a direction to move the dovetailed flanges 11a, 12a of the sections 9, 10 against the surfaces in the groove 8a, the flanges ll, 12 bear against the upper side of the extension 3 and thereby further contribute to prevention of any movement of the column-l with reference to the foot 6. As soon as the clamping action of the sections 9, 10 is relaxed in response to pivoting of the aforementioned tensioning lever, the operator can readily rotate the knob l7 to thereby move the extension 3 and hence the entire column 1 radially of the foot 6, Le, in the axial direction of the spindle 13. The spindle l3 and the internal threads in the tapped bore 14 of the extension 3 furnish a self-locking action so that the, extension 3 remains in the selected position as soon as the rotation of spindle 13 is terminated. The operator is further free to change the angular position of the column 1 by the simple expedient of moving the knob 17 circumferentially of the foot 6 or by turning the upper portion of the column 1 or the machine on the column. In this way, the tool of the machine on the column 1 can be readily moved into accurate register with that portion of a workpiece which is to be provided with a bore or hole. The angular adjustment of I column 1 can precede the lateral adjustment, or vice versa. Both such adjustments can be made as soon as the frictional engagement between the sections 9, 10 of the clamping ring and the extension 8 of the foot 6 is relaxed. As mentioned above, the adjustment which is made in response to rotation of the knob 17 about its own axis remains intact while the column 1 is rotated about its axis because the extension 3 of the base 2 and the spindle 13 furnish a self-locking action. Once the column 1 assumes a desired angular and lateral position, the aforementioned tensioning lever is turned in a direction to move the sections 9, 10 into requisite clamping engagement with the extensions 3 and 8 to thus prevent any undesirable displacements of the column with reference to the foot 6 when the poweroperated machine on the upper portion ofthe column 1 is put to use.

Rotation of the column 1 through full 360 with reference to the foot 6 is prevented by two blocking screws 18, 19 which are shown as being located diam etrically opposite each other and are respectively mounted on the foot 6 and on the section 110. The head of the screw 19 overlies the lower portion of the section 9 and the head of the screw 18 overlies the adjacent upper portion of the foot 6. The head of the screw 18 will strike against the head of the screw 19 in response to rotation'of the column 1 and sections 9, 10 in either direction through an angle of slightly less than 180. Such rotation can take place only when the frictional engagement between the flanges 11a, 12a of the sections 9, l0 and the extension 8 is relaxed.

The purpose of the blocking screws 18, 19 is to prevent rotation of the column 1 through one or more full revolutions with reference to the foot 6. Such rotation could cause undue twisting of an electric cable (not shown) which extends through the foot 6 and column 1 to supply electric current to the machine on the upper portion of the column.

FIG. 2 shows that, when the spindle 13 is rotated in a direction-to move the extension 3 (and hence the entire column 1) to its right-hand end position, the left-hand end face of the upper flange 11 on the section 9 abuts against'the surfacein the innermost'zone of the adjacent portion of the circumferential groove 5 but the flange 12 still extends into the respective portion of the groove 5, namely, into that portion of the groove 5 which is located diametrically opposite the flange 11. This is due to the fact that the depth a is less than the width b. Such dimensioning of the groove 5 and flanges 11, 12 is desirable in order to insure that the sections 9, 10 engage and hold the extension 3 all around its circumference in each and every lateral position of the column 1, i.e., also in the extreme position shown in FIG. 2 or in the other extreme position in which the flange 11 is nearly completely (but not entirely) withdrawn from the respective portion of the groove 5.

FIGS. 3 and 4 illustrate a portion of a modified supporting structure wherein the base 2' of the column 1' has a cylindrical extension 3' of considerable axial length. The sections 9, 10' of the clamping ring have flanges 11, 12 extending into a circumferential groove 5' of the base 2' and these flanges havealigned radially extending channels 15' receiving followers 16' of the base 2'. The sections 9', 10' are connectedto each other by a bolt-shaped connecting member 25 at one end and by means of the tensioning lever 24 at the other end. The lever 24 has a tapped bore and meshes with a threaded post 24a mounted in the section 10'. The lever 24 is further provided with a cam 24b which bears against the adjacent surface of the section 9 and urges the flanges 11a, 12a of the sections 9', 10' against the extension 8' of the foot 6' when the lever 24 is turned in one direction. Turning of the lever 24 in the opposite direction results in a relaxation of frictional "engagement between the extension 8' and the flanges 11a, 12a of the sections 9', 10 so that the column 1 can be rotated about its axis and .can be moved sideways in directions determined by the coupling means including the channels 15' and followers 16 in and crosses in space with the axis of the foot 6 and its extension 8'. One end portion of the shaft 20 extends beyondthe section 9' and is provided with a handgrip portion or knob which can be rotated by hand to thereby move the followers 16f lengthwise of the respective channels 15' and to thus move the column 1' in a direction to the right or to the left, as viewed in FIG. 3 or 4. The extension 3' has a cutout for the pinion 20a and for a portion of the shaft 20. The directions of sidewise adjustment of the column 1' in response to rotation of the shaft 20 and pinion 200 are indicated by a double-headed arrow 23. The pinion 20a and the rack 21. provide a self-locking action which suffices to prevent unintentional sidewise movements of the column 1' with reference to the foot 6'. The electromagnetic means in or on the foot 6 are not shown in FIGS. 3 and 4 for the sake of clarity. The blocking screws 18', 19' serve the same purpose as the screws 18, 19 of FIG. 1. The groove for the flanges 11a, 12a of the sections 9', is shown at 8a.

The supporting structure of FIGS. 3 and'4 can be modified by replacing the shaft 20 and pinion 20a with a worm shaft having a worm which meshes with a worm wheel or with a rack in or on the extension 3' to move the column 1'- laterally in response to rotation of the worm shaft.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features which fairly constitute essential characteristics of the generic and specific aspects of my contribution to the art and,

therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the claims.

What is claimed as new and desired to be protected by Letters Patent is:

1. A supporting structure for power tools, such as boring machines or the like, comprising a foot having electromagnet means energizable to attract the foot to a metallic body, said foot having a first circumferential groove; a supporting member arranged to support a machine and including a base abutting against said foot and having a second circumferential groove; a ringshaped clamping device comprising a pair of arcuate sections provided with first flanges extending into said first groove and with second flanges extending into said second groove with radial clearance to hold said base against movement away from said foot; tensioning means for moving said sections into and from clamping engagement with said foot and with said base to thereby respectively hold said base against movement relative to said foot and to permit sidewise and angular movements of said base relative to said foot; coupling means connecting said sectionswith said base for angular movement therewith; and self-locking adjusting means comprising a rotary portion provided on one of said sections and extending substantially at right angles to the axis of said supporting member and a mating second portion provided in said base and arranged to move with said base sideways in response to rotation of said rotary portion while said tensioning means maintains said sections out of clamping engagement with said base and said foot. v

v2 A supporting structure as defined in claim 1,

wherein said rotary portion of said adjusting means comprises an externallylthreaded spindle having a handgrip portion accessible externally of said one sec- .tion and said second portion ,of said adjusting means comprises an internally threaded portion of said base in mesh with said spindle.

I 3. A supporting structure as defined in claim 1, wherein the width of said second flanges, as considered in the radial direction of said supporting member, exceeds the depth of said second groove.

4. A supporting structure as defined in claim 1, wherein said second portion of said adjusting means is provided with a tapped bore and said rotary portion of said adjusting means'comprises an externally threaded member extending into said bore and having a portion accessible externally of said one section.

' 5. A supporting structure as defined in claim 4, wherein said tapped bore extends radially of said supporting member. I

6. A supporting structure as defined in claim 1, wherein said rotary portion of said adjusting means comprises a pinion rotatable about an axis which crosses in space with the axis of said supporting member and said second portion of said adjusting means comprises a toothed rack provided on said base and extending radially of said supporting member.

7. A supporting structure as defined in claim 1, wherein said coupling means comprises a follower provided on said base and extending into a radially extending channel of one of said sections.

8. A supporting structure as defined in claim 1, wherein said first groove is of dovetailed shape and said first flanges of said sections are of dovetailed outline.

:9. A supporting structure as defined in claim 1, further comprising blocking means for limiting the extent of angular movement of said base with reference to said foot, including a first blocking member provided on one of said sections and a second blocking member provided on said foot and extending into the path of angular movement of said first blocking member with said sections relative to said foot.

10. A supporting structure as defined in claim 1, wherein each of said sections is of substantially semicircular shape and said foot and said base respectively comprise first and second circular disk-shaped extensions having abutting surfaces, said extensions being located between the first and second flanges of said sections. 

1. A supporting structure for power tools, such as boring machines or the like, comprising a foot having electromagnet means energizable to attract the foot to a metallic body, said foot having a first circumferential groove; a supporting member arranged to support a machine and including a base abutting against said foot and having a second circumferential groove; a ring-shaped clamping device comprising a pair of arcuate sections provided with first flanges extending into said first groove and with second flanges extending into said second groove with radial clearance to hold said base against movement away from said foot; tensioning means for moving said sections into and from clamping engagement with said foot and with said base to thereby respectively hold said base against movement relative to said foot and to permit sidewise and angular movements of said base relative to said foot; coupling means connecting said sections with said base for angular movement therewith; and self-locking adjusting means comprising a rotary portion provided on one of said sections and extending substantially at right angles to the axis of said supporting member and a mating second portion provided in said base and arranged to move with said base sideways in response to rotation of said rotary portion while said tensioning means maintains said sections out of clamping engagement with said base and said foot.
 2. A supporting structure as defined in claim 1, wherein said rotary portion of said adjusting means comprises an externally threaded spindle having a handgrip portion accessible externally of said one section and said second portion of said adjusting means comprises an internally threaded portion of said base in mesh with said spindle.
 3. A supporting structure as defined in claim 1, wherein the width of said second flanges, as considered in the radial direction of said supporting member, exceeds the depth of said second groove.
 4. A supporting structure as defined in claim 1, wherein said second portion of said adjusting means is provided with a tapped bore and said rotary portion of said adjusting means comprises an externally threaded member extending into said bore and having a portion accessible externally of said one section.
 5. A supporting structure as defined in claim 4, wherein said tapped bore extends radially of said supporting member.
 6. A supporting structure as defined in claim 1, wherein said rotary portion of said adjusting means comprises a pinion rotatable about an axis which crosses in space with the axis of said supporting member and said second portion of said adjusting means comprises a toothed rack provided on said base and extending radially of said supporting member.
 7. A supporting structure as defined in claim 1, wherein said coupling means comprises a follower provided on said base and extending into a radially extending channel of one of said sections.
 8. A supporting structure as defined in claim 1, wherein said first groove is of dovetailed shape and said first flanges of said sections are of dovetailed outline.
 9. A supporting structure as defined in claim 1, further comprising blocking means for limiting the extent of angular movement of said base with reference to said foot, including a first blocking member provided on one of said sections and a second blocking member provided on said foot and extending into the path of angular movement of said first bLocking member with said sections relative to said foot.
 10. A supporting structure as defined in claim 1, wherein each of said sections is of substantially semicircular shape and said foot and said base respectively comprise first and second circular disk-shaped extensions having abutting surfaces, said extensions being located between the first and second flanges of said sections. 